Variations in the impact strength of material extrusion-type 3d printed specimens depending on tool path and building direction

Articles manufactured by material extrusion (ME)-type 3D printing have limited usage because of their low mechanical strength. In this study, the impact strengths of 3D printing manufactured specimens were examined by fabricating specimens with various building directions and tool paths. The building directions were the width direction and thickness direction of the specimen. There were 13 tool paths including 7 symmetric tool paths and 6 asymmetric tool paths. In addition, the specimen was fabricated by injection molding, and impact strength was compared with the 3D printing manufactured specimens. Cross-sectional morphologies of the 3D printing manufactured specimens were also examined. The lowest impact strength was shown in the specimen fabricated by tool path 90/-90, with building in the thickness direction. Specimens fabricated by tool path 0/0 with building in both directions, and tool path 15/-15 with building in the thickness direction were not broken. Large differences in the anisotropic impact strengths of 3D manufactured specimens were revealed to depend on the tool path and building direction, and it was verified that an impact strength greater than bulk impact strength can be obtained by controlling the tool path and building direction.